Maybe Republicans are right. Maybe liberals aren't constitutionally cut out to be commander-in-chief. Not constitution as in 1787, but constitution as in backbone and gut-check. Panic, it seems, is their natural state. And so it is that every time John McCain lands some good polling numbers they freak out and start talking about leaving for Canada.

There are three reasons why they should calm down.

First, it was always going to be close and those who never understood that are just hanging around with people who agree with themselves too often. Just because 79% think the country is going in the wrong direction doesn't mean they all want it to go in the same direction. And the fact that Bush's approval ratings are at 34% means there is a solid third of the country who will pretty much believe whatever they want to believe.

Obama is a late finisher. Six weeks before the Iowa caucuses he trailed (pdf) Clinton by 6% in Iowa, 19% in New Hampshire and 14% in South Carolina. We all know how that turned out. His campaign relies on field offices and grassroots contact, which takes longer and is more of a slow burn.

But finally, and most importantly, the polls that really matter are not the national but the state polls. The US presidential election is not really a national election but 50 separate local ones. And on that front, even after the conventions Obama is in a commanding position. Obama needs 18 electoral college votes – more than John Kerry – to win. According to pollster.com there is not a single state that Kerry won where McCain is ahead. Conversely, there are two that Bush won – Iowa and New Mexico – where Obama maintains a commanding lead. That's 12 electoral votes. Then there are two – Michigan and New Hampshire – that Kerry won where Obama holds slight leads but which are toss-ups. That's 21 electoral votes. Then there are eight that Bush won – Montana, North Dakota, Nevada, Colorado, Ohio, Florida, Virginia, North Carolina – which are toss-ups. Obama narrowly leads in four, McCain narrowly leads in three. One, Virginia, is a dead heat. That's 95 electoral votes.

In other words, Obama is fighting this election entirely on McCain's territory. McCain is struggling to defend what he has. If they split those toss-ups even 80-20 in McCains' favour he still loses the election.

That doesn't mean Obama's going to walk it. First of all, this year more than most polls are likely to be uniquely unreliable. White people have routinely lied to pollsters about their propensity to vote for a black candidate in a bid to hide their racism. Meanwhile, Obama's base is heavily built on the young and the black who historically have been less likely to turn up than others. One may cancel the other out. The truth is, nobody really knows. (There is some reason to believe the Bradley effect – also known as the Wilder effect (pdf) – no longer holds. I'll believe it when I see it).

In any case, there's a while to go before election day and it is perfectly possible that Obama will lose each roll of the dice. But it's unlikely. What it does mean is that the people who should really be panicking – and who clearly really are panicking because otherwise they wouldn't have picked Sarah Palin as a vice-presidential nominee – are the Republicans. I know which position I would rather be in. Democrats, meanwhile, should have a bit more faith that they have picked the right candidate. Electoral-vote.com, which uses a different method for calculating the slew of polls each day, projects an Obama victory of 281 to McCain's 230 with 27 votes tied. This time back in 2004 they projected Bush on 254 and Kerry on 243 with 41 votes tied. The good news is they got the numbers, if not the individual states, pretty much right back then. The bad news is all the tied votes went to Bush.